Issue OVMF + CSM(seabios), while booting win98: "While initializing device VCACHE: Windows protection error. You need to restart your computer."

[trannks@gmail.com]

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On some UEFI bioses(modern hardware) there is a issue when booting win98: "While initializing device VCACHE:
Windows protection error. You need to restart your computer."

There is this person that has BIOSTAR X470GTA(ryzen) that can boot win98 with bios version 2020(X47BG721.BST). But with bios version 2021(X47BG223.BST) he gets Vcache protection error when trying to boot win98. He rolled back to bios version 2020 and Win98 booted successfully again.

I thought to try to boot win98 in qemu with UEFI+CMS(OVMF+SeaBios) and it happened that I received the same error. I installed bootice(I don't know assembly), on real hardware and in QEMU, both stop at VCACHE: **0028:C03819A6 MOV [EDX+00000100],EAX**

QEMU(64mb ram) OVMF with csm (uefi bios) edk2.git-ovmf-x64-0-20200422.1378.ge54310451f.noarch.rpm( same when building the latest OVMF + CSM):

When building and using seabios.bin(standalone)there is no issue with vcache.
So maybe its a problem with seabios when configured as csm16 module and or with OVMF?

VCACHE is a 32-bit driver disk cache in Windows 9x running in Protected Mode
https://fd.lod.bz/rbil/interrup/windows/20_vx048b.html

Win9x boot process:
http://www.iselfschooling.com/aplus/BootProcessWin9x.htm

There are a bunch of people who run win98 on modern hardware, but on some UEFI(CSM enabled) there is this issue with vcache.(it is not the amount of ram, and there are workaround and patches to limit win98 ram to low values ex 512mb ram). So if issue can be identified and fixed in OVMF+CSM maybe it can give ways to deal with it on real hardware.

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